Is ki a thing or an idea about things? What I take as being at least part of this issue is whether or not ki exists as an objective thing, but I may well be injecting my own questions into the complicated conversation you've been having.

"Ki" is an ancient paradigm that was used to explain how things worked. It became an umbrella-term which included just about every "unknown force" ever encountered (including blood-sugar levels, momentum, electricity, etc., etc.). So when you read "Ki" in the global sense, it is an attempt to suggest some universal thing that encompasses all "unknown forces" in the universe. Unfortunately, this idea doesn't withstand casual scrutiny in the modern western-science paradigm which now prevails and consequently you don't see any serious Asian scholars do anything more than drop the idea of ki/qi like a hot potato.

On the other hand, within that old nomenclature of ki/qi were some unusual discoveries about body mechanics which are obscure enough that our only current approaches are through the old names, as inaccurate and poorly descriptive as they are. The ki/qi in the body should not be confused with the global use of the "ki" or "qi" term. It is an objective, quantifiable amalgam of body abilities, attributes, and relationships (unfortunately it is ALL of those things and thus makes it hard to say any one thing is ki/qi).